On the Consistency of the Exfoliation Free Energy of Graphenes by Molecular Simulations
Monolayer graphene is now produced at significant yields, by liquid phase exfoliation of graphites in solvents. This has increased the interest in molecular simulation studies to give new insights in the field. We use decoupling simulations to compute the exfoliation free energy of graphenes in a li...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-08-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/22/15/8291 |
| _version_ | 1797525519087960064 |
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| author | Anastasios Gotzias Elena Tocci Andreas Sapalidis |
| author_facet | Anastasios Gotzias Elena Tocci Andreas Sapalidis |
| author_sort | Anastasios Gotzias |
| collection | DOAJ |
| description | Monolayer graphene is now produced at significant yields, by liquid phase exfoliation of graphites in solvents. This has increased the interest in molecular simulation studies to give new insights in the field. We use decoupling simulations to compute the exfoliation free energy of graphenes in a liquid environment. Starting from a bilayer graphene configuration, we decouple the Van der Waals interactions of a graphene monolayer in the presence of saline water. Then, we introduce the monolayer back into water by coupling its interactions with water molecules and ions. A different approach to compute the graphene exfoliation free energy is to use umbrella sampling. We apply umbrella sampling after pulling the graphene monolayer on the shear direction up to a distance from a bilayer. We show that the decoupling and umbrella methods give highly consistent free energy results for three bilayer graphene samples with different size. This strongly suggests that the systems in both methods remain closely in equilibrium as we move between the states before and after the exfoliation. Therefore, the amount of nonequilibrium work needed to peel the two layers apart is minimized efficiently. |
| first_indexed | 2024-03-10T09:14:05Z |
| format | Article |
| id | doaj.art-735dfed9db5a4d54a88ed352dfd31734 |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-10T09:14:05Z |
| publishDate | 2021-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-735dfed9db5a4d54a88ed352dfd317342023-11-22T05:46:15ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672021-08-012215829110.3390/ijms22158291On the Consistency of the Exfoliation Free Energy of Graphenes by Molecular SimulationsAnastasios Gotzias0Elena Tocci1Andreas Sapalidis2National Centre for Scientific Research “Demokritos”, Institute of Nanoscience and Nanotechnology INN, 15310 Athens, GreeceInstitute on Membrane Technology ITM–CNR, National Research Council, 87036 Rende, ItalyNational Centre for Scientific Research “Demokritos”, Institute of Nanoscience and Nanotechnology INN, 15310 Athens, GreeceMonolayer graphene is now produced at significant yields, by liquid phase exfoliation of graphites in solvents. This has increased the interest in molecular simulation studies to give new insights in the field. We use decoupling simulations to compute the exfoliation free energy of graphenes in a liquid environment. Starting from a bilayer graphene configuration, we decouple the Van der Waals interactions of a graphene monolayer in the presence of saline water. Then, we introduce the monolayer back into water by coupling its interactions with water molecules and ions. A different approach to compute the graphene exfoliation free energy is to use umbrella sampling. We apply umbrella sampling after pulling the graphene monolayer on the shear direction up to a distance from a bilayer. We show that the decoupling and umbrella methods give highly consistent free energy results for three bilayer graphene samples with different size. This strongly suggests that the systems in both methods remain closely in equilibrium as we move between the states before and after the exfoliation. Therefore, the amount of nonequilibrium work needed to peel the two layers apart is minimized efficiently.https://www.mdpi.com/1422-0067/22/15/8291liquid exfoliationlayered materialsdecoupling simulationsumbrella sampling |
| spellingShingle | Anastasios Gotzias Elena Tocci Andreas Sapalidis On the Consistency of the Exfoliation Free Energy of Graphenes by Molecular Simulations International Journal of Molecular Sciences liquid exfoliation layered materials decoupling simulations umbrella sampling |
| title | On the Consistency of the Exfoliation Free Energy of Graphenes by Molecular Simulations |
| title_full | On the Consistency of the Exfoliation Free Energy of Graphenes by Molecular Simulations |
| title_fullStr | On the Consistency of the Exfoliation Free Energy of Graphenes by Molecular Simulations |
| title_full_unstemmed | On the Consistency of the Exfoliation Free Energy of Graphenes by Molecular Simulations |
| title_short | On the Consistency of the Exfoliation Free Energy of Graphenes by Molecular Simulations |
| title_sort | on the consistency of the exfoliation free energy of graphenes by molecular simulations |
| topic | liquid exfoliation layered materials decoupling simulations umbrella sampling |
| url | https://www.mdpi.com/1422-0067/22/15/8291 |
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